The effects of ethanol and silymarin treatment during gestation on spatial working memory.

BACKGROUND: Using a rat model we have found that the bioflavonoid silymarin (SY) ameliorates some of the negative consequences of in utero exposure to ethanol (EtOH). In the current study our aim was to determine if spatial working memory (SWM) was impaired in offspring whose mothers were maintained on a liquid diet containing EtOH during different gestational weeks. We also determined if SWM was altered with a concomitant administration of SY with EtOH during specific gestational weeks. METHODS: We provided pregnant Fischer/344 rats with liquid diets containing 35% EtOH derived calories (EDC) during specific weeks of the gestational period. A silymarin/phospholipid compound containing 29.8% silybin co-administered with EtOH was also administered during specific weeks of the gestational period. We tested SWM of the offspring with a radial arm maze on postnatal day (PND) 60. After testing the rats were sacrificed and their brains perfused for later analysis. RESULTS: We observed SWM deficits, as well as a significantly lower brain weight in female offspring born of mothers treated with EtOH during the third week of gestation in comparison to mothers treated during either the first or second weeks of gestation. Rats from any group receiving EtOH in co-administration with SY showed no significant deficits in SWM. CONCLUSION: EtOH treatment during the last week of gestation had the greatest impact on SWM. The addition of SY to the EtOH liquid diet appeared to ameliorate the EtOH-induced learning deficits

H2S biosynthesis and catabolism: new insights from molecular studies

Hydrogen sulfide (H2S) has profound biological effects within living organisms and is now increasingly being considered alongside other gaseous signalling molecules, such as nitric oxide (NO) and carbon monoxide (CO). Conventional use of pharmacological and molecular approaches has spawned a rapidly growing research field that has identified H2S as playing a functional role in cell-signalling and post-translational modifications. Recently, a number of laboratories have reported the use of siRNA methodologies and genetic mouse models to mimic the loss of function of genes involved in the biosynthesis and degradation of H2S within tissues. Studies utilising these systems are revealing new insights into the biology of H2S within the cardiovascular system, inflammatory disease, and in cell signalling. In light of this work, the current review will describe recent advances in H2S research made possible by the use of molecular approaches and genetic mouse models with perturbed capacities to generate or detoxify physiological levels of H2S gas within tissue

Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

Changes in the electronic properties of a molecule when it is wired into a circuit

Molecular electronic devices require at least two electrical contacts to one (or more) molecule(s). Single molecules are reliably probed by bonding one end to a gold substrate and the other end to a gold nanocrystal. The circuit is completed with a gold-coated atomic force microscope probe. Measurements of the decay of electronic current with the length of n-alkanedithiol molecules in these single-molecule nanojunctions are reported as a function of the applied bias. The value of the decay constant near zero bias was obtained from measurements in the ohmic region of the current-voltage curves. The electron tunneling decay rate is significantly smaller (βN = 0.57 ± 0.03) than observed for molecules bonded at just one end (βN ≈ 1), and it falls to even smaller values as the applied bias is increased. Both these effects are quantitatively accounted for by a large shift in molecular levels caused by the attachment of wires at each end.link_to_subscribed_fulltex

Iodine-123-metaiodobenzylguanidine scintigraphy in risk stratification of sudden death in heart failure

A metaiodobenzilguanidina (MIBG) é um falso neurotransmissor análogo da noradre-nalina, captada essencialmente por um mecanismo de transporte de tipo 1 na membrana celulardos neurónios adrenérgicos pré-sinápticos, acumulando-se em grânulos de armazenamento decatecolaminas. Como praticamente não é metabolizada, a sua marcac¸ão com um radioisótopo(iodo-123) permite, através de imagens cintigráficas, avaliar de forma não invasiva o status fun-cional da inervac¸ão simpática de órgãos com importante componente adrenérgico, incluindo ocorac¸ão. A sua aplicabilidade em cardiologia nuclear tem vindo a ser estudada e parece revelarimportância na avaliac¸ão de patologias como a doenc¸a arterial coronária, insuficiência cardíaca,arritmias e morte súbita.A insuficiência cardíaca é um problema à escala global, com uma prevalência estimada nospaíses desenvolvidos de 2%. Apresenta uma mortalidade elevada, sendo a morte súbita cardíacaa principal causa. A disfunc¸ão do sistema nervoso autónomo, nomeadamente a hiperatividadesimpática, que acompanha a insuficiência cardíaca crónica, relaciona-se com a remodelac¸ãoprogressiva do miocárdio, o declínio da func¸ão ventricular esquerda e o agravamento dossintomas, participando no desenvolvimento de arritmias ventriculares e morte súbita.Dado que a cintigrafia cardíaca com123I-MIBG permite a identificac¸ão de alterac¸ões do sis-tema adrenérgico cardíaco, questiona-se o seu papel na obtenc¸ão de informac¸ão diagnóstica eprognóstica em doentes com insuficiência cardíaca.Pelo interesse e a atualidade do assunto, pareceu-nos oportuno rever os dados publicadossobre a utilizac¸ão da cintigrafia com123I-MIBG na estratificac¸ão do risco de morte súbita empacientes com insuficiência cardíaca.Metaiodobenzylguanidine (MIBG) is a false neurotransmitter noradrenaline analoguethat is taken up by the ‘uptake 1’ transporter mechanism in the cell membrane of presynapticadrenergic neurons and accumulates in catecholamine storage vesicles. Since it is practicallyunmetabolized, it can be labeled with a radioisotope (iodine-123) in scintigraphic exams tononinvasively assess the functional status of the sympathetic innervation of organs with a signi-ficant adrenergic component, including the heart. Studies of its application in nuclear cardiologyappear to confirm its value in the assessment of conditions such as coronary artery disease, heartfailure, arrhythmias and sudden death.Heart failure is a global problem, with an estimated prevalence of 2% in developed coun-tries. Sudden cardiac death is the main cause of its high mortality. The autonomic nervoussystem dysfunction, including sympathetic hyperactivity, that accompanies chronic heart fai-lure is associated with progressive myocardial remodeling, declining left ventricular functionand worsening symptoms, and contributes to the development of ventricular arrhythmias andsudden death.Since 123I-MIBG cardiac scintigraphy can detect changes in the cardiac adrenergic system,there is considerable interest in its role in obtaining diagnostic and prognostic information inpatients with heart failure.In this article we present a literature review on the use of 123I-MIBG scintigraphy for riskstratification of sudden death in patients with heart failure

Tumor-infiltrating DCs suppress nucleic acid-mediated innate immune responses through interactions between the receptor TIM-3 and the alarmin HMGB1

The mechanisms by which tumor microenvironments modulate nucleic acid-mediated innate immunity remain unknown. Here, we identified the receptor TIM-3 as key to circumventing the stimulatory effects of nucleic acids in tumor immunity. TIM-3 is highly expressed on tumor-associated dendritic cells (DC) in murine tumors and cancer patients. DC-derived TIM-3 suppresses innate immune responses through Toll-like receptor and cytosolic sensor recognition of nucleic acids via a galectin-9 independent mechanism. Instead, TIM-3 interacts with the HMGB1 to interfere with recruitment of nucleic acids into DC endosomes and attenuates the therapeutic efficacy of DNA vaccination and chemotherapy by reducing immunogenicity of nucleic acids released from dying tumor cells. Together, these findings define a novel mechanism by which tumor microenvironments suppress antitumor immunity mediated by nucleic acids